fix: correct get_default_project() query to check for True instead of not NULL

src/basic_memory/repository/project_repository.py

@@ -88,7 +88,7 @@ async def get_by_external_id(self, external_id: str) -> Optional[Project]:
 
     async def get_default_project(self) -> Optional[Project]:
         """Get the default project (the one marked as is_default=True)."""
-        query = self.select().where(Project.is_default.is_not(None))
+        query = self.select().where(Project.is_default.is_(True))
         return await self.find_one(query)
 
     async def get_active_projects(self) -> Sequence[Project]:

tests/repository/test_project_repository.py

@@ -136,6 +136,39 @@ async def test_get_default_project(project_repository: ProjectRepository, test_p
     assert default_project.is_default is True
 
 
+@pytest.mark.asyncio
+async def test_get_default_project_with_false_values(project_repository: ProjectRepository):
+    """Test that get_default_project ignores projects with is_default=False.
+
+    Regression test for bug where is_not(None) matched both True and False,
+    causing MultipleResultsFound when multiple projects had different boolean values.
+    """
+    # Create projects with explicit is_default values
+    project_true = await project_repository.create({
+        "name": "Default Project",
+        "path": "/default/path",
+        "is_default": True,
+    })
+
+    await project_repository.create({
+        "name": "Not Default Project",
+        "path": "/not-default/path",
+        "is_default": False,
+    })
+
+    await project_repository.create({
+        "name": "Null Default Project",
+        "path": "/null/path",
+        "is_default": None,
+    })
+
+    # Should return only the project with is_default=True
+    default = await project_repository.get_default_project()
+    assert default is not None
+    assert default.id == project_true.id
+    assert default.name == "Default Project"
+
+
 @pytest.mark.asyncio
 async def test_get_active_projects(project_repository: ProjectRepository):
     """Test getting all active projects."""